I'm American and was on holiday in India Dec 07 through Jan 08 and visited Shisha a couple of times. The first time (3AM on a Friday morning - we couldn't get in... I don't blame them). However when we tried again a few days later we went a little earlier and found it not a problem to get in.
I recommend Shisha for its music. It's a good mix of house, hip-hop, and bollywood. The crowd is young and there's quite a bit of smoke. I found myself actually craving the smoke-free atmosphere of US clubs when in India... I guess it's still cool to be a smoker here...?